Would Japan still take Papua New Guinea?

In the scenario built around an attack on Sydney, would Japan still take Papua New Guinea?

Yes. Japan would seize Papua New Guinea, wait for an American advance, and counterattack the approaching force.

In the Sydney-attack scenario, Japan would still seize Papua New Guinea while fighting Britain and Australia. Its wider aim would be to let American forces advance toward prepared positions rather than open the campaign by striking them. Japanese forces could then counterattack, damage the American force, and try to break past it toward further objectives. The answer keeps the Australian operation tied to the same logic of making the United States bear the risks of the advance.